About This PhD Project

Project Description

With this project we will make a handshake between two very influential directions of research and (future) technology. Localised magnetic moments embedded in an electronic system belong to the most studied solid state systems. A magnetic moment can provide information on the structure and properties of its surrounding material, which is on the basis of the widely used NMR and ESR/EPR techniques [1]. Yet through the same interaction it can also severely influence the surrounding material. For instance, a disordered environment of nuclear spins (the magnetic moments) is one of the major sources of decoherence of electron spin qubits, limiting the usefulness of the latter for quantum information processing [2]. Nuclear spins or other magnetic moments can undergo jointly with conduction electrons an ordering transition to a novel state of matter, which can become topological [3-6].

This field of mutual strong influence of magnetic moments and correlated electrons has received remarkably little attention to date. In particular, the connection between correlations and the dynamical response of NMR/EPR has never been investigated before, and this will be the entry point for this PhD project.

The most important and also most challenging aspect of this project is the extension of the NMR/EPR theory to incorporate the memory effect of interactions and correlations on the time-resolved NMR/EPR signal. This will require a complete revision of the existing theory, since the assumption of the absence of such a memory effect is one of the first approximations introduced in the fundamental theory. A full understanding of the propagation of quantum coherence through the system will allow us to examine then its potential usefulness for the propagation of quantum information through a dynamical driving of the magnetic moments.